The attachment of a device to ladder uprights to provide additional safety or stability features or to minimize damage to a vertical planate surface is generally known. Illustrations of prior art setting forth such embodiments are U.S. Pat. No. 4,491,192 to Skarsten; U.S. Pat. No. 4,331,217 to Stecklow; U.S. Pat. No. 4,339,020 to Wiseman; U.S. Pat. No. 4,469,194 to McBride; U.S. Pat. No. 4,600,079 to McBride; U.S. Pat. No. 3,419,109 to Costlow, et al; U.S. Pat. No. 4,159,045 to Brooks; and U.S. Pat. No. 4,444,291 to McPherson. Adaptations of this concept have included ladder supports mounted in pairs to the vertical rails or stiles of a ladder, as in the second McBride Patent, listed above; a resilient support attached to the upper rung of a ladder, as in the first McBride Patent, listed above; a combination support step and stabilizer bar, as in the Stecklow Patent, listed above; and a transverse, telescopical support device, as in the Skarsten Patent, also listed above.
Such existing devices are usually constructed of aluminum, wood or other materials from which conventional ladders are made. They tend to be complex in the manner in which they must be affixed to the ladder for each use, requiring utilization of screws, clamps or other time-consuming means of affixation. Existing devices which do not require such time-consuming affixation still generally require adjustment and attachment prior to each use and removal for separate transport and storage. Additionally, many of the prior art applications protrude from the ladder to which they are affixed, changing the attitude or pitch of the ladder against the vertical surface and substituting one safety problem for another. Further, the prior art applications, in distributing the weight of the ladder, tend to either utilize planate support members or support members which distribute weight to a plurality of specific points. None of the prior art utilizes the concept of distributing ladder weight equally along the entire length of an outwardly cylindrical support member to maximize stability and to minimize damage to the vertical surface contacted by the ladder.
The existing prior art fails to provide an apparatus which combines the required benefits of ladder safety and stability with minimization of damage by the ladder to the vertical planate surface which is contacts during use; which can be attached simply and quickly without additional tools; and which can be removed or may be retained on the ladder for transport and storage.
Accordingly, a need exists for a ladder cap attachment, of basic one-piece design, which may be attached without additional tools or apparatus, which may be easily removed, or, alternatively, retained on the ladder for transport and storage, which does not require a significant change in the pitch of the ladder against the vertical surface, and which performs the dual functions of increasing safety and stability and decreasing damage to the vertical surface.